Patent Documents 1 and 2 disclose hydraulic brake systems in each of which a regenerative cooperative control is executed in a state when all of brake cylinders of hydraulic brakes respectively provided for a plurality of wheels of a vehicle are being isolated from a manual hydraulic pressure source.
In the hydraulic brake system disclosed in Patent Document 1, disk brakes are provided for front right and left wheels while drum brakes are provided for rear right and left wheels.
In the hydraulic brake system disclosed in Patent Document 2, a hydraulic pressure of a master cylinder is supplied to the brake cylinders belonging to one of two brake lines while a hydraulic pressure of a power hydraulic pressure source is controlled and then supplied to the brake cylinders belonging to the other of the two brake lines, in a case when a hydraulic pressure booster suffers from in a mechanical failure, or in a case when it is detected whether a fluid leakage is present or absent in a stop state of the vehicle. Further, in the hydraulic brake system disclosed in Patent Document 2, the hydraulic pressure of each of the brake cylinders provided for drive wheels of the vehicle is controlled by using the hydraulic pressure of the power hydraulic pressure source while the master cylinder is held in communication with the brake cylinders provided for non-drive wheels of the vehicle, in a case when a traction control is being executed.
In Patent Document 3, it is disclosed that, in execution of the regenerative cooperative control, the hydraulic pressure of the power hydraulic pressure source is controlled and then supplied to the brake cylinders provided for the drive wheels while a hydraulic pressure of a hydraulic pressure booster is supplied to the brake cylinders provided for the non-drive wheels.